Extensometer is a tool that serves as the detection of a shift in the soil surface, either a shift in the form of land or land falls flowing down in the form of large blocks. This shift sensor utilizing sliding potentiometer that prisoners value will change if the position of contacts can be shifted. When the ground shifts, the data obtained is still an analog data in the form of voltage. This voltage will be converted into digital data by analog to digital converter (ADC) 10-bit microcontroller integrated on ATmega 8535. After that the microcontroller will send a command to display large shift on the LCD display and send it also to your PC through serial communication UART, then the data from these measurements will be accessed through Visual Basic 6.0 programming language and stored in a database automatically secasra. After several measurements were taken, then the sensitivity values obtained from these tools are: every 1 mm shift it produces a voltage of 0.095825 V and a large percentage of error from the data logger is 5,88%.